> On Jun 27, 2017, at 1:03 PM, Adrian Zubarev <[email protected]>
> wrote:
>
> How about?
>
> public func ?? <T>(optional: T?, noreturnOrError: @autoclosure () throws ->
> Never) rethrows -> T {
> switch optional {
> case .some(let value):
> return value
> case .none:
> try noreturnOrError()
> }
> }
>
Yeah, I saw your email right after I sent mine =)
This works, I tried it and also ran the test suite. There was only one error.
var s: String = ns ?? "str" as String as String // expected-error{{cannot
convert value of type 'NSString?' to expected argument type 'String?'}}
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cannot
convert value of type 'String' to expected argument type 'NSString'
I now wonder what the effect on the source compatibility suite would be:
https://github.com/apple/swift/pull/10639
<https://github.com/apple/swift/pull/10639>
Max
>
>
> --
> Adrian Zubarev
> Sent with Airmail
>
> Am 27. Juni 2017 um 21:54:57, Max Moiseev via swift-evolution
> ([email protected] <mailto:[email protected]>) schrieb:
>
>>
>>> On Jun 27, 2017, at 10:38 AM, Xiaodi Wu via swift-evolution
>>> <[email protected] <mailto:[email protected]>> wrote:
>>>
>>> As you write, this operator becomes sugar for “?? fatalError()” once Never
>>> becomes a true bottom type.
>>>
>>> In the meantime, can’t the same thing be accomplished by overloading
>>> fatalError so it’s a generic function that returns a discardable result of
>>> type T, which in turn calls the Never-returning overload?
>>
>> I like this idea more than adding an extra operator, but overloading
>> fatalError won’t work now because of
>> https://github.com/apple/swift/blob/master/stdlib/public/core/Optional.swift#L668
>>
>> <https://github.com/apple/swift/blob/master/stdlib/public/core/Optional.swift#L668>
>>
>>
>>
>>
>>> On Tue, Jun 27, 2017 at 12:25 Erica Sadun via swift-evolution
>>> <[email protected] <mailto:[email protected]>> wrote:
>>> Using an operator to provide feedback on the context of a failed unwrap has
>>> become a commonly implemented approach in the Swift developer Community.
>>> What are your thoughts about adopting this widely-used operator into the
>>> standard library?
>>>
>>> guard !lastItem.isEmpty else { return }
>>> let lastItem = array.last !! "Array must be non-empty"
>>>
>>> Details here:
>>> https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b
>>> <https://gist.github.com/erica/423e4b1c63b95c4c90338cdff4939a9b>
>>>
>>> Thank you for your thoughtful feedback, -- E
>>>
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>>
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